Sacked borders watchdog David Neal said he had “very few” ways of speaking out about his concerns on security.
Mr Neal said “I do stand by” comments he made which were reported in a newspaper article about checks on private jets at London City Airport.
He was dismissed as the independent chief inspector of borders and immigration (ICIBI) last month amid claims he breached the terms of his appointment.
Giving evidence to the House of Lords’ Justice and Home Affairs Committee, he said: “I do stand by what I’d said in the article to the (Daily) Mail.
“The legislation requires me to identify border security failings.
“If I’ve not been able to communicate those failings to the Home Office, either to senior officials, to the director-general of Border Force, or to ministers, then it leaves you with very few angles to go at.”
The Daily Mail reported that data provided to Mr Neal showed Border Force failed to check the occupants of hundreds of high-risk, private jets arriving at London City Airport.
Immigration minister Tom Pursglove said at the time that the Home Office “categorically rejects” this claim, stating that an issue with the data meant flights were wrongly classified.
Mr Neal told peers on Tuesday: “It may well be that it comes out that some of the data was misclassified, but then that is a problem in itself.
“The bread and butter of any risk assessment process has got to be based on appropriate data.
“It’s got to be held at the appropriate level.
“I’m quite sure when the report comes out, we’ll be able to comment on some of those areas.”
After his dismissal, the Home Office published 13 of Mr Neal’s reports on the same day as damning findings from an inquiry into Sarah Everard’s murder by serving police officer Wayne Couzens, leading to claims the Government was trying to bury bad news.
But his report into London City Airport has still not been released.
Mr Neal told the committee: “I’ve had three communications from either the Home Office or the Cabinet Office on not talking about reports that have not been published.”